1. Field of the Invention
The present invention relates to a rewritable optical recording medium system, and more particularly, to device and method for recording data on a rewritable optical recording medium.
2. Background of the Invention
In general, there are rewritable compact disc (CD-RW) and rewritable digital versatile disc (DVD-RW, DVD-RAM, DVD+RW) in optical recording mediums, particularly, in optical disks, which are rewritable freely and repetitively. In those rewritable optical disks, information writing/reading thereto/therefrom are made repetitively as the nature of use of the optical disk is. The repetitive write/read of information causes a change of a mixing ratio of a recording layer mixture provided for recording the information from an initial mixing ratio, which leads to lose initial properties of the mixture, that causes an error occurred in writing/reading information, which is called degradation. Areas of the degradation are turned up as defective areas when formatting, or write or read command for the optical disk is carried out. Other than the degradation, defective areas on the rewritable optical disk are caused by scratch on a surface, dusts, and/or from production defects. Therefore, in order to prevent writing/reading data to/from the defective areas formed by the foregoing causes, management of the defective areas is required. To do this, as shown in FIG. 1, DMAs (Defect Management Areas) are provided in lead-in areas and in lead-out areas of the optical recording medium for managing the defective areas on the optical recording medium. And, data areas are managed in zones, each having a user area for use in actual writing of data and a spare area for use in a case of defect occurrence in the user area. Or alternatively, the spare area may be assigned to a portion of the data area, i.e., to top or bottom. In general, there are four DMAs provided in one disk (for example, a DVD-RAM), two in the lead-in area and the other two in the lead-out area. As management of the DMAs are important, the same data is repeatedly written in the four DMAs for protection of data. Each DMA has two blocks having 32 sectors in total, i.e., one block has 16 sectors. A first block of each DMA (called as DDS/PDL block) includes a DDS (Disk Definition Structure) and a PDL (Primary Defect List), and a second block (called as SDL block) of each DMA includes an SDL (Secondary Defect List). The PDL is a primary defective data storage portion and the SDL is a secondary defective data storage portion. In general, the PDL is in storage of entries of defects occurred in a disk fabrication process and all defective sectors identified in formatting, i.e., initializing and re-initializing, of the disk. Each entry has an entry type and a sector number corresponding to a defective sector. On the other hand, the SDL, listed in block units, is in storage of entries of defective areas occurred after the formatting, or defective areas which can not be stored in the PDL during the formatting. Each SDL entry has one area in storage of a sector number of a first sector in a block having a defective sector occurred therein and the other area in storage of a sector number of a first sector in a spare block which will replace the defective block. The defective areas (i.e., defective sectors or defective blocks) in the data area are replaced with good areas, according to a slipping replacement algorithm or linear replacement algorithm.
Referring to FIG. 2A, in the slipping replacement which is applicable to a case when a defective area is listed on the PDL, if the defective sector listed on the PDL is present in the user area on which an actual data is to be written, the defective sector is skipped, and instead, the defective sector is replaced with a good sector next to the defective sector in writing a data. Consequently, the user area on which the data is being written is pushed backward, to occupy the spare area as much as the skipped defective sector, at the end.
And, referring to FIG. 2B, in the linear replacement which is applicable to a case when a defective area is listed on the SDL, if there is a defective block listed on the SDL present in the user area or in the spare area, the defective block is replaced with block units of replacement areas assigned to the spare area in writing the data. In this instance, though a PSN (Physical Sector Number) assigned to the defective block is not changed, an LSN (Logical Sector Number) is transferred to the replacement block, together with the data. This linear replacement is effective in non-realtime writing/reading a data.
FIG. 3 illustrates a block diagram showing one example of a related art rewritable optical recording disk recording/reproduction device, provided with an optical disk 301, an optical pickup 302, a RF and servo error generating part 303, a data processing part 304, an interface 305, a servo controller 306, a focus servo driver 307, a tracking servo driver 308, and a microcomputer 309 for controlling the above components. There is a host 100 connected to the interface 305 of the optical disk recording/reproducing medium for exchange of commands and data. In this instance, the host 100, one of PC (Personal Computer), supports the optical disk recording/reproducing device.
A signal track of the foregoing optical disk 301 in FIG. 3 has a land and a groove, wherein data can be recorded/reproduce, not only on the land or in the groove, but also on both of the land and the groove. In this instance, under the control of the servo controller 306, the optical pick up directs an optical beam focused by an objective lens to the signal track of the optical disk 301, and an optical beam reflected at a signal recording surface to an optical detector (not shown) for detecting a focus error and a tracking error after focusing the optical beam to the objective lens, again. The optical detector has a plurality of optical detecting elements, each for providing an electric signal proportional to an amount of light incident thereto to the RF and servo error generating part 303, which combines the electric signals to produce a RF signal required for reproduction of a data, and a tracking error signal TE and a focus error signal FE, both required for servo control, and the like. The RF signal is provided to the data processing part 304 for reproduction, and servo error signals, such as FE and TE, are provided to the servo controller 306. The data processing part 304 encodes a data to be written into a recording pulses required by the optical disk 301 and provides to the optical pickup 302, or restores the RF signal into an original data. The servo controller 306 processes the focus error signal FE to provide a driving signal to the focus servo driver 307, and processes the tracking error signal TE to provide a driving signal to the tracking servo driver 308 for tracking control. The focus servo driver 307 drives a focus actuator in the optical pickup to move the optical pickup in up and down directions, for following up the optical disk as the optical disk turns. The tracking servo driver 308. The tracking servo driver 308 drives a tracking actuator in the optical pickup 302 to move the optical pickup 302 in a radial direction, for correcting a position of the beam, to follow up a required track. In the meantime, the host 100 transfers recording/reproduction command to the microcomputer 309 through the interface 305, data to be written to the data processing part 304, and receives a reproduced data. The microcomputer 309 controls the data processing part 304, the interface 305 and the servo controller 306 in response to the write/read command from the host. That is, provided that a data to be written is occurred, the host 100 transfers the data to be written to the optical disk recording/reproducing device, together with a write command. The data to be written may be an A/V data (for example, a movie and the like) requiring a real time recording, or a PC data (for example, a control data or a document file)requiring no real time recording.
FIG. 4 illustrates an example of a related art write command format. The data to be written of being the PC data or the A/V data may be informed to the optical disk recording/reproducing device either by using a write command, or by means of a separate agreement between the host and the optical disk recording/reproducing device. In this instance, the A/V data is written in block units, and the PC data is written in block units or in sector units, which is designated in the write command. The optical disk recording/reproducing device writes the data through a RMW (Read-Modify-Write) process if the data to be written is the PC data in sector units, without fail. That is, a block in which a sector the PC data is to be written therein is read, to check an error, for writing the data in the sector if there is no error in the sector, or after the error is corrected if the error can be corrected. The error correction is carried out in block units. If there is an error in the block, but impossible to correct, or the block is not read at all, no data is written in the block. That is, the data writing is failed. In this instance, after making an error report to the host 100, the optical disk recording/reproducing device writes the data again through the above process after receiving another area assigned by the host 100, or makes a linear replacement to the spare area. On the other hand, the optical disk recording/reproducing device writes the data with, or without the RMW process, i.e., without verification, if the data to be written is the PC data in block units. In this instance, the optical disk recording/reproducing device writes no data in areas with defects by using the PDL and the SDL, which is information indicating defective optical disk. That is, physical sectors recorded on the PDL is skipped in the writing, and physical blocks recorded on the SDL are replaced with replacement blocks assigned to the spare area in writing. The optical disk recording/reproducing device writes the data in the assigned block directly without the RMW process, if the data to be written is the ANV data. Therefore, the data is written in a defective sector included in the assigned block as it is. That is, in this instance too, though the physical sectors recorded on the PDL are skipped in the writing, the physical blocks registered on the SDL are either skipped or have data written thereon as they are. And, though not registered on the SDL, a block having an error in a PID (Physical Identification) which indicates a sector address is taken as a defective block and registers on the SDL, either to skip the block or have data written thereon.
In the meantime, when it is intended to rewrite a PC data on a particular sector in a block having a data written therein directly without the RMW process, the particular sector is subjected to the RMW process, which increases a probability of occurrence of a writing failure of the PC data, particularly, when the PC data is to be written in a particular sector in a block having an A/V data written thereon. And, an error processing, such as this data writing failure, causes a case when no data is written on a sector a data is required to be written therein without fail.